The Columbia Encyclopedia, Sixth Edition. 2001-07.
Arecibo Observatory
radio-astronomy facility located at Arecibo, Puerto Rico, that includes the world’s largest single-dish radio telescope. It was completed in 1963 and is operated by Cornell Univ. under contract with the U.S. National Science Foundation. The principal instrument is a fixed antenna of spherical section, 1,000 ft (305 m) in diameter, that is built into a natural limestone bowl. Although the antenna is too large and heavy to be moved, it can be pointed as much as 20° from the zenith by moving the line feeds to the antenna’s focus. As a result of the resurfacing of the antenna, which was completed in 1974, observations are possible up to a frequency of 4,000 MHz. A 100-ft (30-m) satellite antenna can be used in conjunction with the large antenna for interferometer observations. In addition there is a wide range of instrumentation for measuring ionospheric conditions. Principal research programs include studies of radio emissions from many types of objects, especially the cores of supernovas called pulsars; radar studies of comets and asteroids; and ionospheric studies.
